Well unloading apparatus



July 20, 1965 c. R. LYLES WELL UNLOADING APPARATUS 3 Sheets-Sheet 1 Filed Aug. 19, 1963 ewr ao July 20, 1965 c. R. LYLES 3,195,523

WELL UNLOADING APPARATUS Filed Aug. 19, 1963 s Sheets-Sheet 2 INVENTOR.

CRLYLES BY%MW ATTORNEY y 20, 1965 c:. R. LYLES 3,195,523

WELL UNLQADING APPARATUS Filed Aug. 19, 1963 3 Sheets-Sheet 3 w v m (yo 9 LL FIGZZ I \\\\\\\g Y FIG. 20 FIG. 2/

0 N BY N w 2 N ATTORNEY United States Patent Office Patented July 20, 1965 3,195,523 WELL UNLOADING APPARATUS Cecil Ray Lyies, 2101 E. 16th St., Farmington, N. Mex. Filed Aug. 19, 1963, Ser. No. 393,001 7 (Ilaims. (Cl. 10352) This invention relates to a process of unloading low production oil and gas wells and to gas lift plungers adapted to raise oil well fluid from the bottom of such wells for use in such process.

One object of this invention is to provide an improved method of unloading low production oil and gas wells.

Another object of this invention is to provide improved gas lift plunger.

Yet another object of this invention is to provide gas lift plungers of particular utility in oil wells wherein the gas-oil ratio is particularly high.

Still another object of this invention is to provide sturdy gas lift plungers which are also extremely low in transverse cross-section when the valve thereof is open and in which plungers the major effective portion of the longitudinal cross-section is streamlined.

Other objects of this invention will become apparent to those skilled in the art on the study of the below description, of which description the hereto attached drawings form a part, and in which drawings the same number refer to the same part throughout all the drawings and wherein:

FIGURE 1 is a plan view of one apparatus of this invention with the valve sub-assembly thereof in open position and as seen in the direction of arrow 1A in FIG- URE 9, that apparatus being shown in its normal operative position in a portion of an oil well tubing, said tubing being shown in section along the flat plane shown by line 1B-1C in FIGURE 9 which plane is normal to the direction of arrow 1A;

FIGURE 2 is a side view of the apparatus of FIGURE 1 as seen along the arrow 2A of FIGURE 9, said apparatus being shown with its valve sub-assembly in open position and the apparatus in its operative position in a portion of an oil well tubing, such tubing being shown in section along the flat plane shown by line 2B-2C in FIGURE 9 which plane is normal to the direction of arrow 2A;

FIGURE 3 is a diagrammatic representation of the apparatus of FIGURE 1 during its operation in a well tubing in two of its operative positions therein with its valve in its closed position;

FIGURE 4 is a diagrammatic representation of the apparatus of FIGURE 1 during its operation in a well tubing in two of its positions therein with its valve in open position;

FIGURE 5 is a plan view of the base plate 40 and piston and fork sub-assembly 24 of the apparatus of FIGURE 1 generally as viewed along the arrow 1A and in the plane shown by line lB-IC of FIGURE 9. It is also broken away in part to show, in section the structure of shoulders 57 and 58;

FIGURE 6 is a plan view of the front and rear cross plates 41 and 42 and piston and fork sub-assembly 24 Y of the apparatus of FIGURE 1 as viewed along the arrow 2A and in the plane shown by line 2B-2C of FIGURE 9;

FIGURE 7 is a plan view of the apparatus of FIGURE 1 as seen along the direction of arrow 7A of FIGURE 10, said apparatus being shown with the valve sub-assembly thereof in closed position and the apparatus in its operative position in an oil well tubing, such tubing being shown in section along the flat plane shown by the straight line '7B-7C, which plane is normal to the direction of arrow 7A;

FIGURE 8 is a side view of the apparatus of this invention as seen along the direction of arrow 8A of FIGURE said apparatus being shown with the valve sub-assembly thereof in closed position and the apparatus in its operative position in an oil well tubing, such tubing being shown in section along the flat plane shown by the straight line 8B8C, which plane is normal to the direction of arrow 8A;

FIGURE 9 is a transverse cross-sectional view of the apparatus of FIGURE 1, taken along the broken plane indicated by the broken line 9A-9B-9C-9D in FIGURE 1, with the valve sub-assembly thereof in open position;

FIGURE 10 is an end view of the apparatus of FIG- URE 1 with the valve thereof in closed position, said view being taken along the direction 10A of FIGURE 7;

FIGURE 11 is an enlarged plan view of the valve plate element 1511 taken along the direction of arrow 11A of FIGURE 13;

FIGURE 12 is a side view of the element as seen along the direction of the arrow 12A of FIGURE 13;

FIGURE 13 is an end view of the element 150 taken along the direction of the arrow 13A- of FIGURE- 12;

FIGURE 14 is a side view of the closure plate element 146 viewed along the direction of arrow 14A of FIGURE 16;

FIGURE 15 is a bottom plan view of element 146 taken along the direction of the arrow 15A of FIGURE 14;

FIGURE 16 is an end view of the element 146 taken along the direction of the arrow 16A of FIGURE 14;

FIGURE 17 is a perspective blow-up view of elements of the piston and fork sub-assembly 24 and of the valve sub-assembly 26 in their operative relationships in the apparatus of FIGURE 1;

FIGURE 18 is a cross-sectional view of the apparatus of FIGURE 20, taken along the broken plane indicated by the broken line 18A18B18C-1-8D in FIGURE 20, with the valve sub-assemblies thereof in open position;

FIGURE 19 is an end view of the apparatus of FIG- URE 20 with the valve sub-assemblies thereof in closed position, said view being taken along the direction 19A of FIGURE 22;

FIGURE 20 is a plan view of another apparatus according to this invention with the valve sub-assemblies thereof in open position and as seen in direction of arrow 20A in FIGURE 18, that apparatus being shown in its normal operative position in a portion of an oil Well tubing, said tubing being shown in section along the fiat plane shown by line HIE-20C in FIGURE 18 which plane is normal to the direction of arrow 20A;

FIGURE 21 is a side and sectional view of the apparatus of FIGURE 20 as seen along the arrow 2 1A of FIGURE 18, said apparatus being shown with its valve sub-assemblies in open position and the apparatus in its operative position in a portion of an oil well tubing, such tubing being shown in section along the flat plane shown by line 21B21C in FIGURE 18 which plane is normal to the direction of arrow 21A. This view also shows the apparatus broken away to show in a substantially central section the relations of the intermediate piston rod and the two forks of the piston and fork sub-assemblies;

FIGURE 22 is a plan view of the apparatus of FIG- URE 20 as seen along the direction of arrow 22A of FIGURE 19, said apparatus being shown with the valve sub-assemblies thereof in closed position in an oil well tubing, such tubing being shown in section along the flat plane shown by the straight line 22B-22C of FIG URE 19 which plane is normal to the direction of arrow 22A; and

FIGURE 23 is a side view of the apparatus of FIGURE 20 as seen along the direction of arrow 23A of FIGURE 19, said apparatus being shown with the valve sub-assembiies thereof in closed position and the apparatus in operative position in an oil well tubing, such tubing being shown in section along the flat plane shown by the straight line 23B23C, which plane is normal to the direction of arrow 23A.

The apparatus of FIGURE 1, generally shown as 24 The well tubing is provided with an upper stop 33 at the upper end-of the tubing, and a lower stop 39 such as' a conventional collar stop as shown in US. Patent 2,213,- 580 or, more preferably, as in my copending application- Serial No. 97,287. Y

The upper stop is located in the tubing 32so that the valve sub-assembly 26 of the plunger will not rise above the bottom of the discharge orifice 36 where it opens into the tubing 32'. t

The lower stop is located in the tubing as below. de-

scribed. V The major elements of the cruciform frame sub-assembly 22 are a base plate 40, a frontcross plate .41, and a rear cross plate 42. These elements are firmly joined together to form, as shown in FIGURES 9 and 10, a cruci form sturdy frame, the transverse cross-section of which a is sufliciently small relative to the tubing in which it travels and so shaped as to provide no substantial resistance to passage of fluids therepast. The plunger 20 is dimensioned to fit loosely and slide easily in the tube 32.

The base plate 40 comprises a central or body portion 44, and a fishing neck portion 46 at the front portion of said platethat front portion, in the operative position of the apparatus, is at its top-and a curved rear portion48 that rear portion normally being at the bottom of said apparatus in its operative position.

The base plate 40 is a thin yet sturdylow carbonsteel plate. It is provided with chambers for elements of the piston and fork sub-assembly 24 with slots for location of the cross pieces 41 and 42, and with space for the valve sub-assembly 26. a r r In serial order form the front edge 49 of the plate 50,

the fishing neck portion 46 comprises a fishing head 59,;

a fishing neck shoulder 51 therebelow, and a fishing neck waist 52 below said shoulder. The waist is joined to the body portion 44 by the body shoulders 69 and '70.

The central portion 44 of the base plate is provided with a circular valve plate and fork cavity 56. The body 44 is about four times as wide'as it' is thick and has straight edges 70 and 72. on either side thereof parallel to its length which straight edges are about 2 /2 tin1es as long as the width of the plate 40. The lateral portion of central plate portion 44 is in the preferred embodiment provided with expansible sealing shoulders 57 and 53.

The fishing neck portion 46 of the platelil is provided slot 61 which slot communicates with a top or front piston chamber 63, which chamber in turn communicates with the valve plate and fork cavity 56. a

The rear (normally. the bottom) end of cavity 56 communicates with a cylindrical bottom or rear piston chamber 65 which in turn communicates with the bottom or rear piston slot 67 in the rear portion 48 ofthe body of the The body 44 of base plate 40 is provided with a left 7 shoulder 69 and a right shoulder 71 which extends inward respectively from the left edge 70 and the right edge 72 of the base plate 40 to the outer edge of the waist 52.

with a longitudinally elongated rectangular top or front "bottom edge to slot 1&4.

and fishing neck 46 at an angle of about 45 degrees to v the adjacent side edge 70 or 72. The shoulders 69 and 71 are straight for the major portion of their length but are roundedwhere they join the adjacent edge or waist.

The outer edges of the extensible shoulders 57 and 58 form a readily slidable fit within the tubing 32. Also, the smooth yet slidable contact of the edges 79 and 72 of element ltl and theedges 191 and 103 of elements 41 and 107 and 169 of element 42 with thetubing 32 maintain the. longitudinal axis of the plunger 29 parallel to the longitudinal axis of the tubing 32 and so avoid any substantial canting or tilting of theplunger with respect to the tubing and avoids any locking of the plunger in the tubing during the passage of the plunger through the tubing. Springs 73, -74, 75, and 76, urge the shoulders 57.and 58 out toward the, position shown'in dotted line 79 in FIGURE 5. This movement islimited by the interior wall of the tubing 32. The shoulders 57and 58 thus provide. a smooth yet yieldable'and elastic fit of the apparatus 29 in the tubing "32 andminimize irregular and bumpy movement of the apparatus'therein as might occur with a too loose object travelingrapidly down a string of tubing.

The upper surface 30 of the plate 40, is smooth and, as shown'in FIGURE 10, all but the portions thereof im mediately adjacent plates 42 and 41 are smoothly curved in a smooth taper from its central portion 44 toward its front end 49 and toward its-rear end 68, being Widest at thecentral portion 44 in the preferred embodiment. The lower surface '82 of the'plate 40 is also smooth and smoothly curved and is a mirror symmetrical image of the upper surface 3%). Theleft surface 81 of the members 41 and 42 and the right surface 83 of those members are similarly curved and smooth. Thereby, the major effective longitudinal cross section of apparatus 20 is tapered .for streamline flow of fluid therepast.

At the cavity 56, the upper surface is provided with .a valve plate shoulder 84 and the lower'surface S2 with .a corresponding indentation 85 for the reception therein of the upper valve plate 151' and lower valve plate 152 respectively. The terms upper and lower for the valve plate surfaces are used to refer to the vertical relationship shown in. FIGURE 9, as the so-called upper and lower 'valv'e plates are actually'at the same vertical level When the apparatus is in its intended operating position as shown in FIGURES 3 and 4. I

V The front cross plate 41 and the rear cross plate 42 are thin yet sturdy low carbon steel plates. They have together in their operative positionas shown in FIGURES 1-8, the identical peripheral outline as the base plate 40.

The plates, 41 and 42am arranged in a'cruciforrn manner relative to'the plate 40asshown in FIGURE 10 for plates 49 and 42. V The plate 41 is located transverse to and is firmly attached, as by welding, to the fishing neck and forwardportion of the plate 40. The plate 42 is located transversely of and is firmly attached, as by welding, to the rear portion 4% of the, plate 46) and body 44.

The front plate 41 comprises a body portion and a fishing neck portion 91. The fishing'neckportion coinprises, firmly joined together and in serial order from the front edge 8? of plate 41, a fishing neck head portion 92,

a fishingineck shoulder 94, and a fishing neck waist 96.-

The central portion of the fishing neck portion is provided centrally with a top piston rodchamber 98. The

chamber'93 is open at its top end to edge 89 and at its The body 91) is laterally bounded by portion fill) and an upper. right side plate portion 102.

body portion 44 of the plate 4,0. The width of the slot 61 is the same asthe thickness of the central portion of the plate adjacent thereto, Thereby the plate 41 is firmly located longitudinally of plate 40.

The upper end of the. slot 104 is open to 'theend of upper piston chamber98 andthe central longitudinal axis of thatchamber and of that slot are coaxial with each other.

7 left edge 191 and 1 right edge 103, and comprises an upper left side plate The rear cross plate 42 is a flat plate of the same thickness and peripheral outline as the rear portion of plate 40. It is bounded laterally by left edge 197 and right edge 1tl9 and comprises the rear left side portion 163, the rear right side portion 110, a rearmost portion 112, and a rear central slot portion 114. The rearmost portion 112 has centrally therein a rear piston chamber 116. This chamber is open at its front end to the slot 114. This chamber extends to and is open to the rearmost edge 118 of the member 42.

The plates 40, 41, and 42 are firmly joined together. The sides of the slot 114 of plate 42 fit firmly over and attach to the portion of the body 40 through which the lower piston chamber 65 passes. The plate 41 is firmly attached to the plate 46 with the sides of slot 164 passing over and smoothly embracing the portion of the body 46 through which the piston chamber 63 passes.

The sides of upper slot 61 firmly fit over and are firmly affixed to the portion of the body 41 through which the chamber 98 passes. The slot 67 firmly fits over the portion of the rearmost portion 112 of the body 42 through which portion the piston chamber 116 passes. Plates 4% and 42, and 40 and 41, are joined to each other firmly as by welding.

The rear edges 121 and 122 of the plate portions 1% and 102, and the front edges 124 and 125 respectively of the plate portions 108 and 110 cooperate, when attached to the plate 41) to bound a circular valve space 127. In the open position of the valve sub-assembly 26, as shown in FIGURES 1, 2, 4, and 9, the valve plate sub-assembly components occupy this space.

The front edge 49 of the fishing neck head 50, and the front edge 89 of the body 90 are coplanar as shown in FIGURES 1, 2, and 4. The rear edge 118 of the plate 42 and the rear edge 68 of the body 41) are also coplanar, as shown in FIGURES 3, 7, and 8.

The piston and fork sub-assembly 24 comprises a front piston rod 130, a rear piston rod 132, and a fork 134. The rods 130 and 132 are each straight and cylindrical sturdy low carbon steel rods, each rod fitting smoothly within the cylindrical chamber 63 and 65 provided therefor in the plate 40 and in the chambers 98 and 116 provided therefor in plates 41 and 42, respectively.

The steel fork 134 has laterally projecting teeth 136 and 138 which define a slot 137 therebetween. A yoke 139 joins the teeth. The piston rods 131) and 132 are respectively connected to the front of rear end of said yoke. The fork 134 is also held in position by the plates 151 and 152. Also, the rods 130 and 132 and the chambers 61, 63, 38, and 116 therefor may be square in transverse cross-section to more definitely maintain their orientation and avoid binding. The teeth of the yoke project laterally of the rods 130 and 132 and contact and control the motion of a valve plate control pin 149, which pin is joined to the valve sub-assembly as below described. Rearward motion of the piston rods moves the yoke and its slot and the pin therein to the open valve position shown in solid lines in FIGURE 5 from the closed valve sub-assembly position shown in dotted lines in FIGURE 5. The closed valve sub-assembly position is shown in FIGURES 7, 8, and 10.

The valve sub-assembly 26 comprises a top sub-assembly 142 and a bottom sub-assembly 144. Sub-assemblies 142 and 144 are mirror images of each other.

The valve sub-assembly 142 comprises a valve plate element 150 and a pair of closure plates 146 and 148. The valve plate element 150 comprises a flat circular valve plate 151 with a diametral ridge 153. The lower valve plate element comprises a similar identical size and shape plate 152 with a similarly located and shaped ridge plate 154. The ridge plate 153 is firmly attached to and extends across a diameter of the valve plate 151 and also extends to a somewhat greater length than the diameter of the said plate. The length of the plate ridge 152 (and I 154) is substantially the same as the diameter of the valve space 127. The plate 151 turns smoothly in the circular upper shoulder 84 provided therefor in the plate 41) and plate 152 turns smoothly in the lower shoulder provided therefor on the lower face 82 of the plate 40.

The plate ridge 153 is provided at its end with holes 156 and 157 for attachment thereto of the closure plates 146 and 148. The above mentioned holes have their axes parallel to the top surface of the plate 151. The plate ridge 153 is also provided with vertical spring holes and 161. These holes have their axes normal to the plane or" the plate 151. These spring holes provide for the clastic radially outward urging of the closure plates thereabove.

The valve plate 151 is also provided with a hole 163 and the plate 152 has a corresponding hole 164 for location therein of the valve plate control pin 140 which pin is engaged by the teeth of the fork 134. A snapover pin 166 is a cylindrical pin supported at either end in the top snapover pin hole 167 in plate 151 and at a bottom snapover hole 168 in plate 152. A snapover spring socket 169 in the body portion 44 fixes one end of a snapover spring 170 which spring urges the pin 166 into either the position shown in FIGURE 7 or that position shown in FIGURE 1. The ends of pins 166 and 140 serve to aid to hold the plates 151 and 152 in firm yet smooth contact with the shoulders 84 and 85 in body portion 44 and permit that the plates 151 and 152 smoothly rotate from one position (as in FIGURE 1) to the other (as in FIG- URE 7).

Each of a pair of closure plates 146 and 148, each of which is a mirror image of the other, is firmly yet pivotally held to the plate ridge 153. A corresponding mirror image pair of plates 147 and 149 are similarly attached to the bottom plate ridge 154.

Plates 146, 147, 148, and 149 are identical in structure. The plate 146 comprises two flat side plates 171 and 173 which are curved in peripheral outline as below described and joined by a central section 173 with a similar peripheral outline. The plates 171 and 172 are provided with holes 174 and 175 respectively for a pin 184 which passes therebetween and pivotally holds them to the plate ridge 153. Section 173 fits over the plate ridge 153 with the plates 171 and 173 nesting on either side thereof.

Pin 184 passes between the plates 171 and 173 through the hole 156 therefor in the plate ridge 153. A spring hole 1% in the element 173 serves to nest one end of a compression spring 192, the other end of which nests in the hole 169.

The peripheral edge as 176 of each closure plate, such as 146, is generally circular in outline and covers, due to expansion effected by spring as 192, with adjacent portions of the frame 22, a quarter of a circle, the center of the circle lies on a straight line which passes through the intersection of the fiat plane of the center of plate 40 and the flat plane which passes through the center of plate 41 and plate 42, and the point on that line about which the revolution generating such circle is taken is the point on that center line in the center of the space 127. The diameter of the circle is substantially the same as the internal diameter of the surface of the tubing 32 in order to provide an efiective seal therewith when the springs 192 urge the plates outward.

The edge 176 of plate 146, the edge 177 of plate 147, the edge 178 of plate 148, and the edge 179 of the plate 149 are circular in outline as shown in FIGURE 10 with the center of such circular outline also on the center line or axis of the piston rods 130 and 132. These edges lie firmly yet smoothly against the inner wall 180 of the inner of the tubing 32. As shown in FIGURE 16, the side edges 181 and 183 of element 146 are bevelled at their top. Accordingly, rotation of the plate to the valve closed position shown in FIGURE 7 from that position shown in FIGURE 1, will bring the circular edge 176 into smooth yet elastically yieldable contact with the tubing wall 181).

The plate 172 has a rear L-shaped locking flange 193 7 a a connected by plate extension 195 to the remainder of the side plate 172. The flange. 193 links with acorrespondmg flange 19.4 on member 148, The member 147 is similarly e linked by a flange 197 to. the closure plate 149. V

In operation of the process of this invention the device moves between the bottom stop 39 and the upper surface stop 38. Firstly, a bottomstop 39 is set in the well tubing 32. 'This stop is set at a level" sufiicie'ntly' below the'top level 212 of oil 214 inthe well for location of a plunger 20 with its seal, as the sub-assembly 26, suf ficiently belowi'the top level 212 of the oil in said well tioningforce of the, spring 17.0 theretofore maintaining a the valve subassembly 2 6 in the closed position and q moves thefpiston and fork and valve plates relative to I plates 40, 41, and 42, to. the position thereof shown in FIGURES l and 2 with rod 132 projecting downwards,

to also be 'below the level of saidoil-eallowing for;the

fall of said level during production. However, the 'level of the seal. is maintained above the topof the level of .i. V the perforations in the tubing 33,'openingffrom the tube 32 to the formation 3.4. The stop 39 is usually located above the top level 'of the zone 34.

Thereupon the light plunger 20, 'which has a seal subassembly 26 that in sealing position, as shown in'FIGURE 10, smoothly fits into the interior of tubing 32 and forms a relatively gas tight seal therewith, is placed in the well with its valve sub-assembly 26 in'its open position.

The device 20 with thev'alve sub-assembly 26 in its open position is then dropped from the top of a well as shown at position 200 in FIGURE 4 to the lower position 202 above yet near the lower stop 39. In the posirotated with their outer surfaces parallel to the 'surface of cross plates 41 and 42 as in the position-shown in FIGURES 1 and 2 with a minimum transverse cross-section. A

which is further improved by the curved stream-lined shape of thelongitudinal section of the plates 40, 41, and 42. At the position 202 the bottom tip 204 of the rod 132 projects below the bottoms 68 and 118 of the plates This cross-section provides 'a minimum of resist ance to passage of saiddevice 20 through well. fluids tion 200 the valve-plates146, 147, 148., and 149 are This forceful contact at; position 200111113 automatically rearranges. the components. of the piston and fork subassembly 24 and'th'e components of the valve sub assembly 26 relative to the components of the frame sub-assembly 22'from the arrangement thereof shown in FIG- URES 7 and 8 to that shown in FIGURES .1'and 2. This removes the seal theretofore effected by sub-assembly 26 across the tubing 32.. I ii The weight of the plunger 20 then'drives that plunger from position 200 toward the bottom of the well. The

, extremely small cross-section of the'plunger relative to the internal cross-section of the tubing, as shownin FIG- URE 9, especially coupledwith the. fact that the spaces 223, 224, 225, and 226 available for passage offluids, such as well gas, past the plunger 20 are unobstructed and permit straight line flow of the fluids past the plunger,

provides that the plunger 20 travels down the well with a great velocity even in wells thatproduce 500,000 cubic feet of gas per day against a line pressure of 500 to 550 p.s.i. and permit such downward passage of plunger 20 a without interfering with concurrent upward flowof gases 40 and 42 inthe manner asshown in FIGURES 1 and 2.v

In this position the fork 134 is in the position-shown inv heavy lines in FIGURE 5. The snap-over spring170 serves to, hold the valve sub-assembly 26 in this position. The apparatus 20 freely falls through thewell tubing and the cilia the-tubing'until it meets the lower'collar stop 39, which stop is located slightly above the top of the producing zone 34' and below the usual top level 212 of the oil.214 in the well 30. I

The impact of the movement of the tool20 against the projecting pin 132 overcomes the force of the spring 170 and the end 204 of the rod 132 is driven inward.

This movement of the rod 132 moves the fork .134 forward from the position shown in heavy lines in FIGURE 5 to that shown in dotted lines in FIGURE 5. This the length of the base 40 shown in FIGURE 8. The closure plates 146,147, 148, and 149 are attached to the plate ridge and accordingly move to the full. closedposition shown in FIGURES 7,8, and 10 from the position shown in FIGURES 1, 2, ,and'9. The falling of the' from the formation 34 out of. the well tubing discharge 36. Also, theedges'70, 72, 101,103,167, and 109 of the frame mmebers '40, 41, and 42 fornr-a smooth yet slidable fitwith the, interior surface 180 of the. tubing walls with a minimum of contact area. This structure avoids any 'cantingor locking of the plunger 20 in the tubing 'while still providing a large 'cross-sectionalflarea in the tubing'for flow of fluid past the plunger when the valve sub-assembly thereof is in its open position. The structure of the piston 20 permits that itbe extremely light in weight, although entirely adequately sturdy to perform its intended function of rapid downward passage through thewell to reform a seal across the bottom thereof and, because of such light weight, to require a minimum of pressure for upward drive thereof by the formation gas.

On return to the bottom stop 39 plunger 20 then again is located below the top level212 of the fluid 214 in the well and the cycle of operation above described for. movement of the plunger and the fluid thereabove is again repeated. 7

The large change in cross-section of apparatus 20 between the closed and open position of its valve subplunger down thewell thus results in automatically re-;

the top level 2120f the fluid 214therein.

The orientation shownin FIGURES 7, '8, and 9 of the closure plates 146, 14.7, 148, and 149 in position 207 (at the bottom of FIGURE 3) blocks the' free upward passage of gas and oil.

The gas pressure ,of the.formation, gas then drives plunger 2011p the well as in position 207 with .a load of oil thereabove.(218). This load of oil is unloaded atassembly 26 provides for a particularly rapid passage downward of the apparatus'20.

The simple sturdy structure of the apparatus provides 7 for a great strength with a minimum of weight as well as moving parts. Thestrength permits the absorption by the apparatus of the impact resulting from rapid fall through great heights repeatedly without damage. to the apparatus. Also, this great strength is obtained even though the device is extremely light. This extreme lightnessprovides for a minimum of differential of pres-. 65.

sure required to raise the plunger'and discharge the oil carried thereabove. a V r Y a g The collar stops 38 and 39 have at their'point of contact. with rods and 132a greater width and breadth thanthe diameter of the piston rods 130 and 132 and the, chambers 98 and 116 wherein'those piston rods are supported. Accordingly, the movement of. the. pistons 130 and 132 is limited to the amount by which the ends thereof, as end 216jon rod 130 and 205 on rod 132,

position 209 near the top ofthewell' into a'collector tank or line 220 via the well discharge 36; After the load projects beyond the top edge, as 49 and 89, or the bottom J edge, as 118 and 68, of the elements of the apparatus 20.

Accordingly, after such limited motion of the pistons 1311 and 132, the remainder of the impact due to the motion of the apparatus 20 is absorbed by the members 40, 41, and 42 of the cruciform frame sub-assembly 22.

I In a particular embodiment of the apparatus of FIG- URE 1 for conventional tubing with a nominal 2 inch internal diameter and an actual 1.995 inch external diameter, as for F-25, 11-40, 1-55, and N-80 grade external upset tubing, the dimensions of the apparatus of FIG- URE l are as in Table I.

TABLE I Distance Item Dimension Inches From To- Length 49 68 9 Width..- 70 72 1% Thickne 8O 82 1; Width 101 103 1% Thickness. 81 83 14 Width 107 109 1% Thickness.-. 81 83 1e Length 49 51 )4 Length. 51 1 69-70 1% Diamete 1% Length 49 63 2% Width Vz Length 61 56 1% Internal diameter 6 Length 67 56 1% Internal diameter 1i 1% Width 1%; Straight portion... 5 Curved portion. 1 ,4 Width 1M6 Internal diameter 1% Outside diameter g4 1% Va 1% /1 Length 118 127 2 Internal diameter. e Curvature of edge, diameter of circle matching edge= 1% Diameter gt A0 74c 91c ie "215 its 1%: 14 1% 1 line; B=bottom; T=top in Table I).

Another embodiment of apparatus within this invention is shown in FIGURES 18-23.

The apparatus of FIGURES 18-23, generally shown as I 230, comprises a cruciform frame sub-assembly 231, a

piston and fork sub-assembly 232, and valve sub-assemblies 233 and 234.

The major elements of the cruciform frame sub-assembly 231 are a base plate 240, a front cross plate 241, a rear cross plate 242, and an intermediate cross plate 243.

These elements are firmly joined together to form, as seen in end view in FIGURES l8 and 19, a cruciform sturdy body the transverse cross section of which is sufficiently small relative to the tubing as 32 in which it travels and so shaped to provide no substantial resistance to passage of fluids therepast, as in apparatus 20. Except for modifications in the frame and piston and fork subassemblies to provide for two valve sub-assemblies the structure and operation are the same as above described for the plunger 20.

The base plate 240 comprises a central or body portion 244, a fishing neck portion 246 at the front portion of said plate (said front portion, in the operative position of the apparatus being at the top thereof), and a curved rear portion 248 (said rear or bottom portion normally being at the bottom of said apparatus in its operative position).

The base plate is a thin yet sturdy plate. It is provided with chambers for elements of the piston and fork sub-assembly 232, with slots for location of the cross plates 241, 242, and 243, and with space for the valve subassemblies 233 and 234.

In serial order from the front edge 249 of the plate 24a), the fishing neck portion 246 comprises a fishing head 250, a fishing shoulder 251, and a fishing neck waist 252.

The central portion 244 of the base plate is provided with a front valve plate and fork cavity 255 and a rear valve plate and fork cavity 256. The lateral portions of central plate portion 244 are provided with expansible sealing shoulders 257 and 258 identical except for length to items 57 and 58 in plunger 20. Intermediate portion 245 separates cavities 255 and 256. The fishing neck portion 46 of the plate 40 is provided with a longitudinally elongated rectangular top or front slot identical to the slot 61 above discussed, which slot communicates with a top or front piston chamber identical to 63 above discussed in said plate 40 which chamber in turn communicates with the front valve plate and fork cavity 255.

The rear (normally the bottom) end of cavity 256 communicates with a cylindrical bottom or rear piston chamber 65 which in turn communicates with the bottom or rear piston slot 67 in the rear portion 248 of the body of the plate 240. This slot extends to the bottom or rear edge 268 of the base plate 240.

The body 244 of base plate 240 is provided with a left shoulder 269 and a right shoulder 271 which extends inward respectively from the left edge 270 and the right edge 272 of the base plate 240 to the outer edge of the waist 252 of fishing neck 246 at an angle of about 45 degrees to the adjacent edge 270 or 272. The shoulders 269 and 271 are straight for the major portion of their length but are rounded where they join the adjacent edge and waist.

Springs 73, 74, 75, and 76 above described urge the shoulders 257 and 258 outward to provide a smooth elastic fit of the apparatus 230 in the tubing 32 and minimize irregular and bumpy movement of the apparatus 230 therein as above described for plunger 20.

The upper surface 280 of the plate 240 is smooth and the lateral portions thereof are smoothly curved in a smooth taper from its central portion 244 towards its front end '249 and towards its rear end 268, being widest at the central portion 244 in the preferred embodiment. The lower surface 282 of the plate 240 is also smooth and smoothly curved and is a mirror symmetrical image of the upper surface 280. The left surface 281 of members 241, 242, and 243, and the rig-ht surface 283 of those members are similarly curved and smooth.

At each of the cavities 255 and 256, each of which is identical to cavity 56 for plunger 20, the upper surface 284) is provided with a valve plate shoulder as 284 and the lower surface 282 with a corresponding shoulder 285 for the reception therein of upper valve plate 351 (151 in plunger 20) and a lower valve plate 352 (152 in plunger 20) respectively. The terms upper and lower for the valve plate surfaces are used to refer to the vertical relationship shown in FIGURE 18 as the s-o-called tudinal axis of that chamberand upper valve plate is actually atvthesame vertical level when theappar-atus is in its intended operating position.

The front cross plate 241, therintermediate cross plate 243, and the rear cross plate 242 form togethernin their operative position as shown in FIGURES 21 and 23 the identical peripheral outline as the base plate 240. The plates 241, 242, and 2.43am arrangedin a cruciform manner relative to the plate 240, as particularly clearly shown in FIGURE 19 for plates 240 and 242. The plate 241 is arranged tranverse to and is firmly attached to the forward portion of the plate 240. The plate 24-2 is arrayed transversely of and is firmly attached to the'rear portion 24% of the plate 240.v The'in'termediate oross plate 243 is arranged in line with plates. 2 41 and 242 and firmly attached to intermediate portion 245 of portion 2440f plate 240. 1

The front cross plate 241 is The rear cross plate 242 is identical to rear cross plate 42 of plunger 24} in outline and structure.

The inter-mediate'cross plate 243 comprises an upper identical to plate 41' in plunger 20 in outline and internal structure.

aieegeae The piston and fork sub-assembly 232 comprises a front piston rod- 330, a rear piston rod 332, an intermediate piston'rod 333, a front fork 334, and a rear fork 335.

" Rods 3370 and 332 are each straight and-cylindrical in seca front and rear of fork 335. The, forks each project laterally'of the rods to which connected and each controls the motion of a valve/plate control pin 340- and 341, respectively, which pins are. joined to the valve sub-assemblies as below describm. The rearward motion of the pistons moves the forksand .the slots and the pin therein to the open valve position from the cl-osed'valve position, as above described for plunger 20, and the forwing U plate portion 291 and a lower-wing plate portion 7 293 and a slot 292-therebetween at their forward end.

The width of the slot 292 is the same as the thickness of the intermediate body portion 245 of the plate 240. Portions 291 and 293 are solidly joined rear w-ardly of'the slot by a bridge 294 through whichintermediate piston rod chambers 225 passes. Chamber 295 is like 63 and 65 7 "of plunger 2% relative to the rod therein.

The forward end of the slot 222 is fully open to the? chamber 335 of plate 24th The rear end of slot 292 is open to piston rod chamber 295 and the central longiof that slot are coaxial with each other. I

The intermediate portion'245' of body 244 is a The front bridge portion 394 has therein a piston rod chamber 305. Chamber 3195 is open at its front end to the chamber 255' and extends to and-is open to the front edge of chamber 295' The rear edges 1-21 and 122 of the plates Hi0 and 162 (of plate 241) and the front edges 2% and 297 respec tively of the wings 291 and 293 cooperate, whenattachcd to the plate 24%} to bound a front ,circular valve space 299. In the open position of the valve'as' shown in FIG- URES 18, 21, and 20,- the front valve plate sub-assembly components occupy this space.

The rear edges 31-1 and 313 of the wings 291'and 29 3 and the front edges 124 and 125 respectively of the plates 108 and 110 of cross plate 242 cooperate, when attached to the plate 240 to bound a rear circular valve space 3%.

'In the open position of the valve as s-hoWn in FIGURES 18, 21, and the rear valve plate sub-assembly components occupy this space.

flatplatej of the same thickness and peripheral outline aslt-he'other f central portion'siof plate 240. It is comprised of a left wing portion 3%, a rear wing portion 302, a front bridge portion 394, and a central rear slot portion 3%.

ward motion of piston rods. 330; 332, and 333 moves the yokes 334 and 335 and the valve sub-assemblies 233 and 234 to their closed position from their open position as abovedescribed tor plunger 20; h

The valve sub-assemblies233 and 234 comprises a top sub-assembly 142 and a bottom sub-assembly 144 .ex-

actly as in'plunger 20.1 Sub-assemblies 142 and 144 are mirror images of each other. V I K In operation the device 230 moves betweenithe bottom stop and the upper surface stop 38 in the same manner as plunger 20. V V V I The maintenance of the fixed angular relation of the valve subaassembly and the {tubing achieved by the great .ength of the straight portion of the body of plates 40, 41 and 42 (and 240; 241, and 242) relative to thethick- V ness of those plates and the close fit of the plate with the interior of the tubing permits the tube to travel down the The plates 246,241, 242, and 243 are firmly joined together as in plunger 26 with the slot in cross plate 242 fitting firmly over the portion of the body z tilthrough which the lower piston chamber as 65 passes. :T he plate 241 is firmly attached to the plate24 with the slot The passing over and smoothly'supported on the. portion of the body 249 through which the piston chamber 63 passes.

The cavities 255 and 256 are separated by the bridge poitubing smoothly. and rapidly. I

The firm (yet slidable) location 'of eachvalvesubassembly 25, 233, and 234, relative to their frame sub- 7 assembly and of said frame sub-assemblies to the tubing in their sealingpositi-ons, as shown in FIGURES 7,8, 10, 19, 22, and, 23, achieved by the great length of the straight portion of the plates 40, 41, and 42 (and 240, 241,

and 242), relativeto their thickness and the close yet I sl-idablefit of the frames'with the tubing maintains such sealing sub-assemblies in a fixed angular relationship to the interior of the tubing. -This maintenance of a fixed angular relationship of sealing element to tubing inf-proves the sealing effect substantially (over the use of similar seals in an apparatus which fits soloosely in a tubing as to allow variations of the angle of the seal with the tubing) and so makes optimum use of the formation gas pressure to unload oil as'above described for plunger 20.

The elements146 and 148 'are'also'urged apart'by a lateral extension spring 198, which spring is located in a socket 19am thebody section 173 of the element 146.

"Corresponding element 148 is provided a corresponding spring 198A to resiliently urge the elements as 146 and 148 di arnetrically apart across the tubing and so to pro- 7 videa resilient seal with the surface 180. Similar springs tions 304 and 294. These bridge portions serve as points of firm attachment of the pieces 243 and 245 to each other, as by welding, in the'sa-me manner as plates 240 and 241, and 24th and 242 are joined to each other. The cavities 255 and.256 rotata-b-ly accommodate the valve assemblies 233 and-234 respectively therein in the same manner as cavity 56 accommodates sub-assembly 26.

The front edge'249'of the fishing neck head 250, 1and the front edge 289 of the body 241 are coplanar as shown in FIGURES 2023. v I

and sockets are also providedv in the other closure plate element-s 147and 149. 1 j V The apparatuses 20 and 230 of this invention permit that when the well is turned on, i.e., when its control valve 344 for discharge 36 isfopen, to permit flow through, the

' discharge 36, the apparatus 20 (or 230) operates continuously as above described in relation to FlGURES 3 and 4 (in column 7, line 5 to column '8, line 52, inclusive), The

cycle time for the apparatus 21) to complete a cycle such as shown in FIGURES ,3 andx4',.i.e; starting from position 200 atlthe top-of the well and going to thebottom position 202, picking-up a load of liquid and returning to the top and discharging, is cont-rolled by the rate of flow permitted by the discharge valve 344. Thus, this apparatus does not require an auxiliary or motor valve to cause the fluid flow from the well to be intermittent for these apparatuses to operate as these apparatuses may operate with the gas flow from the well being continuous. These apparatuses are designed to return from the surface against a substantial flow of well fluids upwardly through the well from the formation 34 above described, because of their low cross section and, also, the faired shape of the frame elements and their fixed angular relation to the longitudinal axis of the tubing, whereby they provide a minimum of interference with the flow of fluid from the well. For instance, the apparatus of FIGURE 1 falls rapidly through a nominal 2 inch internal diameter tubing from wells producing from 500,000 to 1,000,000 cubic feet of gas per day into a line pressure of 500 to 550 p.s.i., such wells providing only one (42 gallon) barrel of oil per each 2,000 to 10,000 cubic feet (at standard temperature and pressure) of gas while permitting such wells to discharge uninterruptedly. When such wells have intermittent discharge in order to permit a fluid unloading apparatus to return to the bottom of the well, such Wells have a substantially long shut-in time during which there is no discharge nor production of the well. With this apparatus there is no such shut-in time unless, of course, the well is shut in for some other reason.

This apparatus permits production operation with continuous flow of the well and discharge from the surface orifice 36 and does not require intermittent flow of gas from such a well. This avoidance of intermittent flow in such wells avoids problems of freezing and mechanical shock concomitant on partial release of pressure on high pressure gas in such operation. Also, the continuous noninterm ittent flow provided by the apparatuses and method of this invention, by avoiding any substantial blocking of gas flow during the time the liquid unloading apparatus travels down the well, does not interrupt or interfere with the production of the well and provides the economic benefits concomitant on such uninterrupted production.

It is within the scope of this invention that the cross sectional area of the frame of the apparatuses 20 and 230 may be reduced to below the 59.6 percent above given for the particular embodiments of FIGURES 123 in order to reduce further the lack of interference of the operation of such apparatuses with the production of the well.

The apparatuses 20 and 230 contact only a small portion of the adjacent tubing-only 2.0 lineal inches of contact along a 6.28 inch long surface in the embodiment of FIGURES 123. Hence, on downward travel of such apparatuses through oil well tubing these apparatuses do not remove or substantially downwardly displace the usual oil film on the inner surface 180 of the tubing 32, while the resilient seal contacting all the tubing surface provided by the resiliently expansible closure plates 146, 147, 148, and 149, in their sealing positions, does provide for effective upward movement of the oil contacted and carried thereby.

Although, in accordance with the provision of the patent statutes, particular preferred embodiments of this invention have been described and the principles of the invention have been described in the best mode in which it is now contemplated applying such principles, it will be understood that the operation, constructions and compositions shown and described are merely illustrative and that my invention is not limited thereto and, accordingly, alterations and modifications which readily suggest themselves to persons skilled in the art without departing from the true spirit of the disclosure here-inabove are intended to be included in the scope of the annexed claims.

I claim:

1. A well unloading tool for use in a well tubing, said well tool comprising a frame sub-assembly, a valve subassembly and a valve control sub-assembly, said frame subassembly comprising a first flat plate and a second flat 14 plate, said first flat plate and said second fiat plate each having a width slightly less than the diameter of said tubing and slidably fitting therein and each said plate having a length greater than its width and thickness less than its width, said first plate being firmly attached to said second plate along a line parallel to the length of said tool,

said valve sub-assembly comprising a pair of valve portions, each of said portions comprising a valve closure plate and a valve support plate, each of said closure plates being supported on one of said valve support plates, each said valve closure plate and its valve support plate being semi-circular in outline, said out-line substantially matching the internal cross s ction of the well tubing with a smoothly sl-idable fit, each said valve support plate being circular in outline and rotatably supported on .said first flat plate for rotation about an axis normal to said line of attachment of said first and second flat plates and to the plane of width and length of said first plate and each said valve supporting plate being attached to and perpendicular to a closure plate, a circular orifice passing through said first plate, one valve support plate rotating on one side of said orifice and another valve support plate rotating on the other side of said orifice, said valve support plates fixedly attached to each other for rotation together, .an orifice in said second plate, means'supported on said frame urging said valve support plates into a position either parallel to or transverse to the first and second plates, and said valve control means movably supported by said frame and operably connected to said valve supporting plates and controlling the position of said plates, said valve control means comprising means sensitive to the position of said tool in said tubing.

2. Apparatus as in claim 1 wherein the maximum transverse cross section of said frame occupies less than 60% of the cross Sectional area within said tubing and said closure plates rotates entirely within said orifice in said second plate.

3. Apparatus as in claim 1, there being a lug on said valve support plate and said valve control means comprising a lug engaging means and rods projecting from said lug engaging means through said frame to the ends thereof and projecting from the upper end thereof when the valve sub-assembly is in its position transverse to the first and second plates and from the rear end in the position of the valve sub-assembly parallel to said first plate.

4. Apparatus as in claim 1 comprising also elastic means on one of said frame sub-assembly plates yieldably and elastically urging a lateral portion thereof radially outwards into contact with said tubing, said frame sub-assembly plates each having a lower end and a middle portion, the lower end of said frame sub-assembly plates being narrower than the middle portions thereof, each of said first and second plates having a substantially straight lateral edge portion with a length greater than the width of said plate.

5. A well unloading tool for use in a well tubing, said Well tool comprising a frame sub-assembly, a pair of valve sub-assemblies and a valve control sub-assembly, said frame sub-assembly comprising a first flat plate and a second flat plate, said first flat plate and said second flat plate each having a width slightly less than the diameter of said tubing and slidably fitting therein and each having a length greater than its width and a thickness less than its width, said first and second plate having the same peripheral outline, and said first plate being firmly attached to said second plate along the center thereof, the lower end of said frame plate being smoothly narrowed,

each of said plates having a substantially straight lateral edge portion with a length greater than the width of said plate, the lateral portions of each of the plates being smoothly curved and tapered from one dle thereof to the other end thereof to provide a minimum of resistance to fluid flow therepast,

each said valve sub-assembly comprising apair of valve portions, each of said portions comprising a valve closure plate and a valve support plate, each of said closure plates being supported on one of .said valve support plates, said valve closure plates each being semi-circular inpoutline, said outline substantially matching the internal cross section of the tubing with a smoothly slidable fit,

each said valve support plate being, circular in outline and rotatably supported on said first plate for rotation about an axis normal to the length of the tool and a plane determined by the width and. length I of said first plate and each said valve supporting plate being pivotally attached to and perpendicular to a closure plate, said closure plates being parallel to each other,

a plurality of circular orifices passing through said first p1ate,;:one valve support plate rotating on one'side Y of eachsaid orificeand another valve support plate rotating, on the other-'side of each of said orifice,

' ;said"v.alve support plates being fixedly" attached 'to each other for rotation together, a plurality of orifices in said second plate said closureplates fitting within said orifice when-parallelH-to the length of said. tool, "chambers in the plates of, said frame and valve; control means ,rnovably supported in; said chambers operably connected to said valvesupport l V i port'plates, means supported on said frame urging said valve support plates into a position either parallel to or transverse to the length of said tool, saidjvalve control means comprising means sensitive to the position offsaid tool in said tubing. 7 6.;Apparatus as in claim 5' wherein saidvalve controlmeans comprises a pluralityof valve support engaging means and rods projecting between-said valve support engaging means and from said valve support engaging means through the chambers in' saidframe to the ends thereof and projecting from the upper end thereof when each 'valve sub-assembly is in its laterally extended position and fromthe lower end in the position of the valve closure plates is parallel the length of the tool.

7'. Apparatus as in claim 5 wherein the maximum transverse cross section of saidframe'occupies less than 0f the cross sectional area within said tubing and said valve control sub-assembly rotates said closure plates entirely Within said orifices in said second plate.

References Cited hy the Examiner 7 UNITED, STATES PATENTS "2,762,308 9/56 Tomlinson 1o3 52 2,791,131 5/57 Knox 103 52 2,937,598 5/60 'Brown ..a 103-52 3,012,513 12/61 Knox 10s 52 LAURENCEVV. EFNER, Primary Examiner.

.30 ROBERT M. wALKERpExam iner. plates and controlling the position of said valve sup-1 C 7 I r I 

1. A WELL UNLOADING TOOL FOR USE IN A WELL TUBING, SAID WELL TOOL COMPRISING A FRAME SUB-ASSEMBLY, A VALVE SUBASSEMBLY AND A VALVE CONTROL SUB-ASSEMBLY, SAID FRAME SUBASSEMBLY COMPRISING A FIRST FLAT PLATE AND A SECOND FLAT PLATE, SAID FIRST FLAT PLATE AND SAID SECOND FLAT PLATE EACH HAVING A WIDTH SLIGHTLY LESS THAN THE DIAMETER OF SAID TUBING AND SLIDABLY FITTING THEREIN AND EACH SAID PLATE HAVING A LENGTH GREATER THAN ITS WIDTH AND THICKNESS LESS THAN ITS WIDTH, SAID FIRST PLATE BEING FIRMLY ATTACHED TO SAID SECOND PLATE ALONG A LINE PARALLEL TO THE LENGTH OF SAID TOOL, SAID VALVE SUB-ASSEMBLY COMPRISING A PAIR OF VALVE PORTIONS, EACH OF SAID PORTIONS COMPRISING A VALVE SUPPORT PLATE AND A VALVE SUPPORT PLATE, EACH OF SAID CLOSURE PLATES BEING SUPPORTED ON ONE OF SAID VALVE SUPPORT PLATES, EACH SAID VALVE CLOSURE PLATE AND ITS VALVE SUPPORT PLATE BEING SEMI-CIRCULAR IN OUTLINE, SAID OUTLINE SUBSTANTIALLY MATCHING THE INTERNAL CROSS SECTION OF THE WELL TUBING WITH A SMOOTHLY SLIDABLE FIT, EACH SAID VALVE SUPPORT PLATE BEING CIRCULAR IN OUTLINE AND ROTATABLY SUPPORTED ON SAID FIRST FLAT PLATE FOR ROTATION ABOUT AN AXIS NORMAL TO SAID LINE OF ATTACHMENT OF SAID FIRST AND SECOND FLAT PLATES AND TO THE PLANE OF WIDTH AND LENGTH OF SAID FIRST PLATE AND EACH SAID VALVE SUPPORTING PLATE BEING ATTACHED TO AND PERPENDICULAR TO A CLOSURE PLATE, A CIRCULAR ORIFICE PASSING THROUGH SAID FIRST PLATE, ONE VALVE SUPPORT PLATE ROTATING ON ONE SIDE OF SAID ORIFICE AND ANOTHER VALVE SUPPORT PLATE ROTATING ON THE OTHER SIDE OF SAID ORIFICE SAID VALVE SUPPORT PLATES FIXEDLY ATTACHED TO EACH OTHER FOR ROTATION TOGETHER, AN ORIFICE IN SAID SECOND PLATE, MEANS SUPPORTED ON SAID FRAME URGING SAID VALVE SUPPORT PLATES INTO A POSITION EITHER PARALLEL TO OR TRANSVERSE TO THE FIRST AND SECOND PLATES, AND SAID VALVE CONTROL MEANS MOVABLY SUPPORTED BY SAID FRAME AND OPERABLY CONNECTED TO SAID VALVE SUPPORTING PLATES AND CONTROLLING THE POSITION OF SAID PLATES, SAID VALVE CONTROL MEANS COMPRISING MEANS SENSITIVE TO THE POSITION OF SAID TOOL IN SAID TUBING 